Overview

This report provides exploratory and preliminary correlation analyses between sex hormones and T2 unretouched, raw hippocampal subfield data from the Healthy Aging Study sample (subjects 333 - 437, with 438 appended).

Black diamond points are the group means. Highlighted in purple triangle point and purple line is subject 438. Note that subject 438 was on estrogen HRT at the time of her scan and blood draw.

Cleaning data steps included:

  1. Filter participants that have T2 subfield data from scan
  2. Select sex hormone measures from when scan was conducted
  3. Correct left and right volumes with TIV
  4. Average left and right volumes to get an average measure for each subfield region

Sample size:

  • Men = 24

  • Women = 63 (24 pre, 20 peri, 19 post)

Hormone Distributions

Reproductive Status

For women, hormones will be log transformed to allow for Pearson correlations to run in the subsequent analyses (by reproductive stage)

Men and Women

For any correlation analyses between women and men, hormones will also be log transformed for Pearson correlations.

Men Only

For just men, log transformation will also be applied in the following Pearson correlations

T2 Subfield Volume

CA1

Subject 438: average volume of 0.6379874

Structural Comparison

Df Sum Sq Mean Sq F value Pr(>F)
repo_status 2 0.0151012 0.0075506 1.520983 0.2268011
Residuals 60 0.2978570 0.0049643 NA NA

ANOVA results comparing CA1 subfield by reproductive status was not significant.

## 
##  Welch Two Sample t-test
## 
## data:  avg_ca1 by sex
## t = 3.216, df = 52.242, p-value = 0.002232
## alternative hypothesis: true difference in means between group Female and group Male is not equal to 0
## 95 percent confidence interval:
##  0.01761859 0.07607124
## sample estimates:
## mean in group Female   mean in group Male 
##            0.5872078            0.5403629

T-test results comparing CA1 subfield by sex was significant.

Hormone Correlation by Reproductive Status

Hormone Correlation by Sex

CA2/3

Subject 438: average volume of 0.2456474

Structural Comparison

Df Sum Sq Mean Sq F value Pr(>F)
repo_status 2 0.0019035 0.0009517 0.493987 0.6126484
Residuals 60 0.1155978 0.0019266 NA NA

ANOVA results comparing CA23 subfield by reproductive status was not significant.

## 
##  Welch Two Sample t-test
## 
## data:  avg_ca23 by sex
## t = 2.5392, df = 48.975, p-value = 0.01434
## alternative hypothesis: true difference in means between group Female and group Male is not equal to 0
## 95 percent confidence interval:
##  0.004920838 0.042268912
## sample estimates:
## mean in group Female   mean in group Male 
##            0.2467289            0.2231340

T-test results comparing CA23 subfield by sex was significant.

Hormone Correlation by Reproductive Status

Hormone Correlation by Sex

DG

Subject 438: average volume of 0.7845671

Structural Comparison

Df Sum Sq Mean Sq F value Pr(>F)
repo_status 2 0.0083941 0.0041971 0.750208 0.4766459
Residuals 60 0.3356715 0.0055945 NA NA

ANOVA results comparing DG subfield by reproductive status was not significant.

## 
##  Welch Two Sample t-test
## 
## data:  avg_dg by sex
## t = 2.0854, df = 43.206, p-value = 0.04298
## alternative hypothesis: true difference in means between group Female and group Male is not equal to 0
## 95 percent confidence interval:
##  0.00119681 0.07118450
## sample estimates:
## mean in group Female   mean in group Male 
##            0.6192800            0.5830894

T-test results comparing DG subfield by sex was significant.

Hormone Correlation by Reproductive Status

Hormone Correlation by Sex

ERC

Subject 438: average volume of 0.4945524

Structural Comparison

Df Sum Sq Mean Sq F value Pr(>F)
repo_status 2 0.0407582 0.0203791 4.123448 0.0209918
Residuals 60 0.2965350 0.0049423 NA NA

ANOVA results comparing ERC subfield by reproductive status was significant.

## 
##  Welch Two Sample t-test
## 
## data:  avg_erc by sex
## t = 3.5175, df = 55.723, p-value = 0.0008746
## alternative hypothesis: true difference in means between group Female and group Male is not equal to 0
## 95 percent confidence interval:
##  0.02204370 0.08038099
## sample estimates:
## mean in group Female   mean in group Male 
##            0.4655728            0.4143605

T-test results comparing ERC subfield by sex was significant.

Hormone Correlation by Reproductive Status

Hormone Correlation by Sex

PHC

Subject 438: average volume of 1.676401

Structural Comparison

Df Sum Sq Mean Sq F value Pr(>F)
repo_status 2 0.0516381 0.0258191 0.6318458 0.5351094
Residuals 60 2.4517754 0.0408629 NA NA

ANOVA results comparing PHC subfield by reproductive status was not significant.

## 
##  Welch Two Sample t-test
## 
## data:  avg_phc by sex
## t = 2.2998, df = 38.699, p-value = 0.02694
## alternative hypothesis: true difference in means between group Female and group Male is not equal to 0
## 95 percent confidence interval:
##  0.01419269 0.22180438
## sample estimates:
## mean in group Female   mean in group Male 
##             1.674716             1.556717

T-test results comparing PHC subfield by sex was significant.

Hormone Correlation by Reproductive Status

Hormone Correlation by Sex

PRC

Subject 438: average volume of 1.842525

Structural Comparison

Df Sum Sq Mean Sq F value Pr(>F)
repo_status 2 0.211709 0.1058545 0.7813027 0.4624106
Residuals 60 8.129078 0.1354846 NA NA

ANOVA results comparing PRC subfield by reproductive status was not significant.

## 
##  Welch Two Sample t-test
## 
## data:  avg_prc by sex
## t = 0.50652, df = 39.953, p-value = 0.6153
## alternative hypothesis: true difference in means between group Female and group Male is not equal to 0
## 95 percent confidence interval:
##  -0.1378815  0.2301021
## sample estimates:
## mean in group Female   mean in group Male 
##             1.652974             1.606863

T-test results comparing PRC subfield by sex was not significant.

Hormone Correlation by Reproductive Status

Hormone Correlation by Sex

SUB

Subject 438: average volume of 0.3528027

Structural Comparison

Df Sum Sq Mean Sq F value Pr(>F)
repo_status 2 0.0060737 0.0030368 1.392181 0.2564443
Residuals 60 0.1308814 0.0021814 NA NA

ANOVA results comparing SUB subfield by reproductive status was not significant.

## 
##  Welch Two Sample t-test
## 
## data:  avg_sub by sex
## t = 2.8303, df = 53.988, p-value = 0.006517
## alternative hypothesis: true difference in means between group Female and group Male is not equal to 0
## 95 percent confidence interval:
##  0.007799812 0.045688732
## sample estimates:
## mean in group Female   mean in group Male 
##            0.3732318            0.3464875

T-test results comparing SUB subfield by sex was significant.

Hormone Correlation by Reproductive Status

Hormone Correlation by Sex

Summary

  • Subregion volumes for women and men were generally normally distributed. There appears to be two women whose SUB volumes appear to be outliers. Hormones were generally right skewed, so log transformations were applied to run Pearson correlations.

  • No significant trends seen in Pearson correlations for DHEAS.

  • No significant trends seen in Pearson correlations for men.

  • ANOVA results comparing subfields by reproductive stage were not significant for almost all subfields. ANOVA results for ERC was significant by reproductive stage (p < 0.05).

  • T-test results comparing subfields by sex were all significant (at least p < 0.05) except for PRC.

  • For estradiol, it was significantly negatively correlated with CA1 for peris (p = 0.036) and with DG for peris (p = 0.04), and marginally negatively correlated with CA23 for peris (p = 0.065).

  • For progesterone, it was significantly positively correlated with CA1 for posts (p = 0.033) and with ERC for posts (p = 0.015).

  • For FSH, it was significantly negatively correlated with ERC for posts (p = 0.015) and with PHC for posts (p = 0.045). PHC volume and FSH were marginally negatively correlated among women as a group (p = 0.062). FSH is also marginally negatively correlated with CA1 for posts (p = 0.08) and with SUB for posts (p = 0.074).

  • For testosterone, it was marginally positively associated with DG for pres (p = 0.066).

  • For SHBG, it was significantly negatively correlated with ERC for posts (p < 0.01). It was also negatively correlated with PRC among women as a group (p = 0.028) and marginally negatively correlated with PRC for pres (p = 0.057).